Forage and Livestock
Livestock production risks are also associated with seasonal climate variability. Drought and high temperatures affect both beef and dairy cattle. High returns from beef and milk production are more difficult during dry years (La Niña phase) in the Southeast because much of the production is based on grazing. High temperatures cause heat stress in cattle, reducing feeding, growth, and live births.
Climate variability is important in determining success in pasture and hay production and is another way in which climate affects livestock production. Check the topics listed in the side menu for more information. The table below shows typical seasonal climate variability in the Southeast.
Beef cattle production is often constrained by drought and cold temperatures. SECC researchers used optimization models to investigate the potential of seasonal climate forecasts to aid rancher management decisions. Although many potential adaptations exist in response to seasonal climate forecasts, conversational surveys with cattle producers allowed us to narrow our focus to four areas of potentially feasible management adjustments. These were stocking rate, winter forage management, fertilization, and purchasing of hay or other winter feed ahead of time.
The model used by SECC researchers showed that seasonal climate variability forecasts could aid beef cattle ranch management decisions by:
- Helping decide on more plentiful stocking during El Niño good rainfall seasons
- Helping make more informed decisions on when to plant winter forage especially in El Niño years when good production and stocking possibilities exist
- Increasing savings by buying hay ahead of time before a La Niña dry winter/spring.
Climate forecast-based Beef Cattle Management
|Management||Adaptation to Seasonal Climate Variability|
|El Niño (cooler-wet fall/winter)||La Niña (hot-dry winter/spring)|
|Stocking Rate||Stock 7-10% more cattle.||Stock 12-15% less cattle.|
|Plant Winter Forage||Planting likely to succeed and produce forage.||Less chance of establishment.|
|Fertilizer Winter Forage||Good response likely from grass.||Losses may be compounded.|
|Buy Winter Feed||Little advantage to purchasing ahead of winter.||Purchasing ahead of time is good strategy.|
Climate Effects on Pasture Production and Stocking Rates
A case study: Model of a North Central Florida Ranch
Ryegrass planting is a critical activity within the cow-calf operation because this is one of the best forage alternatives for the winter months. Ryegrass establishment and production are partially associated with El Niño/La Niña phases.
SECC researchers developed a simulation model of a typical 400-acre cow-calf operation in north Central Florida. Bahiagrass can carry approximately 8 to 10% more cattle in either El Niño or La Niña years than it can in neutral years; this is why ranchers customarily plan for neutral summers, as it represents the worst case scenario. The rye-ryegrass mix on the other hand, carries about the same number of head in a neutral year as in an El Niño year. In La Niña winters, carrying capacity is greatly reduced. By planning ahead according to an expected La Niña winter prediction, ranchers could buy hay or other feed in the summer, which ordinarily costs much less than they would pay in winter.
In the model, when La Niña was predicted, the model planted nearly 75% of the 400 acres to rye-ryegrass, whereas for El Niño a little less than 30% was planted. This fact has important connotations for economic outcome because more stockers can be carried over the winter with good weight gains and subsequently higher prices when sold in spring. The great variability in herd size is accounted for mostly in the number of calves carried through winter and heifers during the summer in the different probabilistic scenarios.
Modeled herd size over 40 years of known climate effect.
When the rancher follows the recommendation to plant winter forage and the climate prediction is correct, the incurred costs will be from planting on time and there are no unexpected costs. When the rancher follows the recommendation and the ryegrass is not established because the prediction was not accurate, the rancher not only loses the money of planting the ryegrass, but also he or she needs to buy expensive hay in the winter to maintain the herd. In the case that the rancher does not follow the recommendations and does not plant any ryegrass, meaning that he or she buys cheap hay in the summer (preparing for the winter), there are no unexpected costs.
Overall, end value is doubled (or more) when recommendations are followed and are correct versus the case where the rancher does not follow recommendations. The worst-case scenario is when the rancher follows recommendations and establishment fails due to incorrect climate predictions. These results represent a “perfect case” and do not take into account probabilities of occurrence or relative strength of a particular El Niño or La Niña event.